Large numbers (20 digits)

you can do two thing

1)you can use strings as numbers what i mean is you"ll have to write all the operations for strings like <+,-,*,/,%>
and then you"ll have large numbers

2)you can take your string breake it to ints then do the opertion on them and build back the string

i would use the frist one i did it in the past in pascal it's not that hard

Thanks.

Those were the options I already know that can be done (not sure how), but I'm looking easier way :) I'm not making class library for handling large numbers and I only need this functionality in one function, so I'm not really interested in how it is implemented as long as it works.

IMO in OO Programming one should try to use code written by others and not spend time reinventing the wheel (which would become quite angulate :), especially if the problem is just a small part of the whole program. Of course doing something yourself teaches you, but I have to draw the line somewhere and try to learn things that are more important to my current projects.

If you want only to add one (or two :) ) to this number, you can add it to charcode of last digit in it. And then if last digit bigger than '9', set it to zero and add 1 to previous digit.
Something like this:

last = strlen(str_number);
str_number[last]++;
while( str_number[last] > '9' )
{
  str_number[last] = '0';
  last--;
  str_number[last]++;
}
 

i think you still can use my first idea
if you want to use only operator + it very easy to do

it like:

 123
+
 999
----
1122

you sum the last entry and move 1 or 0 to the next entry

make that_i64toa()- sorry...

oops - looks like the original comment got dropped -

If you have __int64 support (Microsoft specific), you could use _atoi64() and _i64toa() to do it...

No Microsoft in HP-UX 11 :)

HP-UX has LARGE_INTEGER, though, I believe... it's a quadword type of struct. As for API support, you would check the OS docs for that. Various flavors of UNIX treat this differently... check into that and let me know if that helps...